A communications protocol stack can be an implementation of a particular computer networking protocol suite. Individual protocols within a suite can each have a defined purpose. Such modularization of functionality can facilitate design and implementation. In the protocol stack, a given module may communicate, for example, with two other modules (e.g., a module above the given module and a module below the given module). A lowest level of the protocol stack deals with, for example, hardware interactions. Every higher layer adds more features. A highest level of the protocol stack deals with, for example, application considerations. For some protocols, each layer can be considered a media (e.g., lowest), a transport (e.g., middle), or an application (e.g., highest) layer.